1. 1. Combine Starter and Water: In a large mixing bowl, gently whisk together your active sourdough starter and the warm water until the starter is mostly dissolved and the mixture looks milky. This ensures even distribution of the starter throughout your dough.

2. 2. Add Flour and Salt: Add the bread flour and fine sea salt to the wet mixture. Use a sturdy spoon or your hands to mix everything until a shaggy dough forms and no dry flour remains. It will be sticky and a bit messy at this stage.

3. 3. Initial Rest (Autolyse): Cover the bowl with a clean kitchen towel or plastic wrap and let the dough rest for 30 minutes. This “autolyse” period allows the flour to fully hydrate, making the dough easier to work with and helping with gluten development.

4. 4. First Set of Folds: After the rest, lightly wet your hands. Gently grab a portion of the dough from one side, stretch it upwards, and fold it over itself towards the center of the bowl. Rotate the bowl a quarter turn and repeat this stretching and folding action 3-4 more times, until you’ve gone all the way around. The dough will start to feel a bit smoother and more elastic. Cover and let rest for 30 minutes.

5. 5. Repeat Folds (3-4 Times): Repeat the stretching and folding process every 30-45 minutes for a total of 3-4 sets. With each set, you’ll notice the dough becoming progressively stronger, smoother, and more elastic. It will hold its shape better. After the last set of folds, cover the bowl and let the dough rise at room temperature until it has almost doubled in size, which can take 2-4 hours depending on your kitchen temperature and starter activity. Look for a bubbly surface and a jiggly texture.

6. 6. Shape the Loaf: Lightly flour your work surface. Gently turn the dough out onto the flour. Carefully shape the dough into a round or oval loaf. The goal is to create surface tension, so gently pull the edges of the dough towards the center and then flip it over, using the surface tension to create a smooth, taut top.

7. 7. Prepare for Baking: Preheat your oven to 450 F (230 C) with a Dutch oven or heavy pot inside for at least 30 minutes. Carefully transfer your shaped dough to a piece of parchment paper, then gently lower it into the preheated Dutch oven. Score the top of the dough with a sharp knife or razor blade (a simple “X” or a single slash works great) to allow for expansion.

8. 8. Bake the Bread: Cover the Dutch oven with its lid and bake for 30 minutes. Remove the lid and continue baking for another 10-15 minutes, or until the crust is deeply golden brown and sounds hollow when tapped on the bottom. Carefully remove the bread from the Dutch oven and transfer it to a wire rack to cool completely before slicing. This cooling step is crucial for the internal structure to set.